Downscaling 4k files

cp2

Member
I am on the verge of ordering a 4k disc (The War of the Worlds (1953)) that only comes as a 4k disc. I do not have a Blu-Ray version already as I think that at the time it came out there were strong indications that a 4k version would be forthcoming in due course ( and, from my recollection, the disc wasn't cheap and I try to be frugal).
I like to have a non-4k version available as I also have a Full HD only set so I decided to experiment with downscaling a 4k ripped file using Handbrake but leaving it in H265. I had a particular concern in mind and it looks like I was right. The resultant 1920x816 output played OK on my 4k TV but the HDR flag on the TV lit up.
I then tried a full downscale to H264 but the HDR flag still came on so my doubts about the integrity of the picture remain.
I am yet to try to play the file on my second TV thoughI have little doubt that it will play, though of course it will almost certainly not recognise the HDR element of the file, which calls into question the accuracy of the picture. Given that it is a 22" set (!!) I may not be able to best assess this.
Whilst downscaling from 3840 to 1920 is do-able will the output be less than it could be?
 

cp2

Member
I've now watched the files on my small Full HD TV. As I expected both files played onthe TV but the picture looked rather washed out, lacking in colour. It looks like Handbrake can downscale the pixel count and change H265 to H264 but the HDR "punch" does not translate.
I'm better off sticking with my broadcast quality version of the film.
 

jmc

Well-known member
I checked the website for my main video processing program and it does list HDR.
I have never had a HDR video file so can't say anything about results.

"TMPGEnc Video Mastering Works 7
The best encoder - now with HDR editing and 8K output support."
 

cp2

Member
Handbrake also processes HDR but the output file retains the separation, hence the output files still lighting up the HDR icon when played on a TV that can process it. If the TV cannot process HDR (i.e. non 4k) then it will not light up and an element of the colour pallete will be lost. How much this will be depends on the extent of the HDR content. Expecting the video editor to merge the HDR into the main video when downscaling is probably unrealistic.
I recently downloaded a Dolby Vision demo file. Sure enough the Dolby Vision icon lit up and the resultant picture was stunning on my LG TV using an NAS drive as the dile source, as befits a 60 second demo. However, I have devices that do not support Dolby Vision and through them the picture was dire as the colours were clearly wrong. It seems to me that the file used only DV in its coding rather than treating it as a bonus layer over HDR10.
My setup currently does not support DV as well as I would want it to: just another thing to fret about.
 
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